Aircraft autopilot systems generally make it possible to keep the aircraft on a trajectory and with a pre-established speed by developing and sending orders to control surfaces of the aircraft.
These systems lighten the workload of the crew, and allow the crew to focus on tasks other than keeping the aircraft in flight along a given trajectory.
Generally, the autopilot system operates in a given movement domain of the aircraft, in particular regarding the angle of climb and bank angle. When the aircraft is outside this movement domain, the aircraft is piloted manually and the autopilot system is deactivated.
To ensure that the flight is conducted in complete safety, the crew must see, at all times and in three dimensions, the current movement of the aircraft, in particular in terms of angle of climb, pitch attitude, and bank angle. This allows him to take appropriate measures to maintain the attitudes of the aircraft, or on the contrary to modify them when necessary to conduct the flight.
Under certain extreme conditions, the crew of the aircraft may be spatially disoriented, due to outside events or through a simple loss of spatial perception of the attitudes of the aircraft. For example, when the aircraft moves through fog, the crew may find itself without outside references and therefore be disoriented.
Such disorientation sometimes leads the crew to make piloting decisions affecting the proper conduct of the flight, or even undermining its safety.
To offset this problem, some known avionics systems provide a particular autopilot mode, which can be activated upon pressing a specific button in the cockpit, to perform a recovery maneuver. This maneuver generally consists of leveling the wings, to obtain a zero bank angle and level the aircraft again with a zero angle of climb. The crew may then resume control of the aircraft.